JPH11176675A - Small-sized noncontact transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smaller noncontact transmitter by constituting a ferrite core, a coil, and an electric circuit board integrally so as to materialize downsizing of a transmission part and reduction of number of parts enough. SOLUTION: In a noncontact type of transmitter which includes coils 2 and 3 opposed to each other across space and one hand of which serves as input or transmission side and the other hand of which serves as output or reception side, and transmits signals or power or both at the same time, making use of the electromagnetic inductive action generated between opposed coils 2 and 3, the ferrite cores 11 and 11' equipped with coils 2 and 3 and patterns for electric circuits are constituted, by baking powder molded items.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized non-contact transmission device for transmitting electric power, a signal, or both at the same time in a non-contact manner by electromagnetic induction generated between coils.

[0002]

2. Description of the Related Art A coil formed by winding a rectangular ferrite core is opposed via a gap, one of which is arranged as an input side coil and the other is arranged as an output side coil. 2. Description of the Related Art There is known a transmission device that performs non-contact transmission by utilizing. This device is configured using an electric circuit board such as a flexible printed circuit board (FPC) dedicated for mounting the coil and accompanying electronic components.

[0003]

Conventionally, a ferrite core used in the above-described non-contact transmission device has a saturation magnetic flux density (B) and a magnetic permeability (μ) in order to increase the inductance and reduce the DC resistance of the coil. ) Employ Mn-Zn ferrite cores, each of which is a large material. Therefore, the electrical resistance of the core is low (about 0.1 Ω · m), and the coil and the accompanying electronic components cannot be directly arranged on the core, and a flexible electric circuit board is used as an insulator. I was

Furthermore, Mn-Zn ferrite can be sintered only in a sintering furnace in an atmosphere (inert gas), and cannot be supplied in large quantities at low cost.

Accordingly, the present invention has been made to solve the above problems, and the technical problem thereof is that a ferrite core and a coil are required to sufficiently reduce the size, weight, and number of parts of a transmission unit. Another object of the present invention is to provide an even more compact non-contact transmission device by integrally configuring the electronic device and an electric circuit board.

[0006]

According to the present invention, a coil is formed by printing a conductor in the form of a comb or a spiral on a ferrite green sheet, and the electric circuit board is also printed in the same manner, and then fired. Configure the circuit. Further, according to the present invention, a non-contact transmission device in which a magnetic flux passes through the inside of a comb-shaped or spiral coil printed and sintered on a ferrite green sheet is obtained, and the above-described magnetic circuit is configured. Accordingly, the magnetic flux generated from the coil almost passes through the core and contributes to transmission without leaking to the outside. In the present invention, by selecting the number and connection method of the printed coils, the firing temperature of the magnetic material to be mounted on the coil, the thickness of the magnetic material, and the configuration of the output side circuit, a remarkable transmission in the non-contact transmission is performed. It has been found that efficiency can be improved.

That is, according to the present invention, there is provided a coil which is opposed via a gap, one of which is an input side or a transmission side and the other is an output side or a reception side. In a non-contact transmission device for transmitting a signal or electric power or both at the same time, a substrate for providing the coil and an electric circuit including the coil is formed by firing a ferrite powder molded body. A non-contact transmission device is obtained.

Further, according to the present invention, in the compact non-contact transmission device, the coil and the circuit wiring portion constituting the electric circuit and the substrate are made of NiO, CuO, Zn.
Ag powder is contained in a spinel ferrite green sheet containing O and Fe ₂ O ₃ as main components, or
A compact non-contact transmission characterized by being printed with a conductor paste containing g powder and Pd powder so as to form the coil and a circuit wiring portion that is a conductor of the electric circuit, and integrally fired in the air. A device is obtained.

Further, according to the present invention, in any one of the above-mentioned compact non-contact transmission devices, each of the input side coil and the output side coil is constituted by at least one plane meander coil or plane spiral coil. Thus, a compact non-contact transmission device is obtained.

Further, according to the present invention, in any one of the above-mentioned small non-contact transmission devices, the circuit wiring portion formed on the substrate has, on the output side, a connection portion for mounting a resonance capacitor and an external connection. A small non-contact transmission device characterized in that a connection part and an external connection terminal part for mounting a resonance capacitor, a detection / rectification diode, and a smoothing capacitor are provided on an input side. can get.

Further, according to the present invention, in any one of the above-mentioned compact non-contact transmission devices, the coil, the circuit wiring portion, and the substrate are made of an integrally fired ferrite core, and a frequency used for transmission is 100 kHz or more. Thus, a compact non-contact transmission device characterized by the following is obtained.

Further, according to the present invention, in the compact non-contact transmission device, the integrally fired ferrite core may have a diameter of 0.1 mm.
A compact non-contact transmission device characterized by having a thickness in the range of 1 to 5 mm is obtained.

Further, according to the present invention, there is provided a small-sized non-contact transmission device according to any one of the above-mentioned ones, wherein a method is used in which a contact which contributes to transmission is eliminated.

Further, according to the present invention, in any one of the above-mentioned compact non-contact transmission devices, the integrally fired ferrite core reduces a leakage magnetic flux generated from an electric circuit on the input side and the output side to 40% or less. A small contactless transmission device characterized by the above feature is obtained.

Further, according to the present invention, in any one of the above-mentioned small non-contact transmission devices, a component constituting the electric circuit or a component connected to the electric circuit is replaced with a surface of the substrate on which the coil is formed. 0 to 2 mm on the other surface facing
A small contactless transmission device characterized by being configured so as to be able to be arranged via the gap of (1) or being able to be arranged separately from the substrate.

Further, according to the present invention, in any of the above-mentioned small non-contact transmission devices, the gap between the coils is 0 to 5 mm (not including 0). Is obtained.

In summary, according to the structure of the present invention, a printed coil with ferrite which is integrally fired is arranged so as to face each other on an input side and an output side, and a plurality of printing coils are connected to form a plurality of facing coils. In a set of coils composed of a plurality of opposing sets, connections are made so that the directions of magnetic flux between adjacent coils are reversed, and a capacitor is inserted in the output side of the print coil. And the thickness of the integrally fired ferrite core to be mounted is set to 0.1 to 5 (mm).

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing a configuration of a small contactless transmission device according to an embodiment of the present invention. FIG. 2 is a perspective view showing the receiving unit of FIG. FIG. 3 is a perspective view showing the transmission unit of FIG. FIG. 4 is an equivalent circuit diagram of the small contactless transmission device of FIG.

As shown in FIG. 1, a small contactless transmission device 1
0 is the receiving unit 20 on the output side and the transmitting unit 3 on the input side
0. The small non-contact transmission device 10 is configured to perform non-contact transmission using an electromagnetic induction effect generated between coils 2 and 3 that are opposed to each other via a gap, for example, a meander coil.

As shown in FIG. 2, a small contactless transmission device 1
No. 0 receiving unit 20 includes a coil 2 composed of a meander coil composed of a conductor formed on one surface of the ferrite core 11;
And a circuit conductor 4 forming a conductor pattern of an electric circuit connected to the coil 2 composed of a meander coil. The circuit conductor section 4 includes diode connection sections 13 and 13 for mounting the rectification / detection diode 12 and smoothing capacitor connection sections 15 and 1 for mounting the smoothing capacitor 14.
5, a connection portion 17 for a resonance capacitor for mounting a resonance capacitor 16 for resonating at a frequency of 100 kHz or more as a transmission frequency, and external connection terminal portions 18 and 19
Are formed. Each of these connection parts 13, 15, 1
7 includes a smoothing capacitor 14 and a resonance capacitor 1 respectively.
6, and the rectifying / detecting diode 12 are mounted respectively, and constitute an electric circuit.

Here, in the embodiment of the present invention,
Ni-based ferrite is used as the ferrite core 11. The reason for selecting Ni-based ferrite as such a magnetic material is that Ni-based ferrite has excellent high-frequency characteristics such as high electric resistance (5 MΩ · m or more) and particularly large μ in a frequency band of 200 KHz or more. This is because there is an effect of preventing magnetic flux leakage. The thickness of the Ni-based ferrite core used in these small non-contact transmission devices 10 is preferably 0.1 to 5.0 mm. The reason is that when the thickness is 0.1 mm or more, the effect of capturing magnetic flux is clearly recognized, but when the thickness is 5 mm or more, the effect of reducing the thickness is significantly reduced.

The Ni-based ferrite is made of a ferrite green sheet (main component composition ratio: 22NiO.9Cu).
O.20ZnO.49Fe ₂ O ₃ ) with a conductor (100% A)
g of powder ink or 90% Ag-10% Pd powder ink) is printed in a spiral or comb shape, and the circuit conductor for the electric circuit is also printed. For a conductor made of 100% Ag powder ink, about 880 ° C, 90% Ag-10%
In the case of a Pd powder ink conductor, it is fired in air at about 950 ° C. to form an integrally fired ferrite core in which the coil, the circuit conductor, and the ferrite core are integrated.

As shown in FIG. 3, the transmitting unit 30 includes a conductor pattern formed on one surface of the ferrite core 11 ', for example, a coil 3 composed of a meander coil and a wiring pattern of an electric circuit connected to the coil 3. Circuit conductor part 5
And The circuit conductor portion 5 has a resonance capacitor connection portion 22 for mounting a resonance capacitor 21 for resonating at a frequency of 100 kHz or more as a transmission frequency.
And external connection terminal portions 24 and 25 are formed respectively.
The resonance capacitor 16 is mounted on the resonance capacitor connection portions 22 and 22.

The integrally fired ferrite core constituting the transmitting section 30 is also manufactured by integrally firing using the same ferrite green sheet and conductor as the receiving section 20 shown in FIG.

The transmission unit 20 and the reception unit 30 shown in FIGS.
As shown in FIG. 1, the above components are mounted on the circuit conductors 4 and 5 of the integrally fired ferrite core, and the coils 2 and 3 are mounted.
Are arranged so as to face each other.

As shown in FIG. 4, the transmission section 20 is connected to a frequency conversion circuit 6 having an external signal power supply connection section 7 at one end. The transmitting unit 20 and the receiving unit 30 transmit and receive via the coil 2 and the coil 3 facing each other.

In addition, as shown in FIGS. 2 and 3, in the transmitting unit 20 and the receiving unit 30, the coils 2 and 3 formed by opposing printing have a meander type (comb type) shape (meander type). Coil), but a spiral coil can also be used. The reason is that if a plurality of printed coils are densely arranged on the same surface, the amount of magnetic flux increases correspondingly, and the magnetic flux contributing to transmission can be increased.

In the case of the small-sized non-contact transmission device 10 according to the embodiment of the present invention, the transmission efficiency is remarkably improved for the reasons described later. For example, if the opposing coils 2 and 3 include an output-side portion, a configuration (not shown) in which a capacitor is inserted into the output-side portion may be mentioned.

In some of these small non-contact transmission devices, the transmission efficiency is improved by the integrally sintered ferrite cores on the input and output sides. The reason is that coils 2 and 3
This is because the magnetic flux generated by the magnetic flux passes through the ferrite cores 11 and 11 'in a concentrated manner, so that the leakage magnetic flux can be reduced to 40% or less.

On the other hand, although not described in the description corresponding to the figures, when a planar comb coil or a spiral coil is constituted by a plurality of comb coils or a plurality of spiral coils facing each other, the generated magnetic fluxes are all in the same direction. And a method of connecting the magnetic fluxes adjacent to each pair in the opposite direction. The latter configuration has the advantage that the magnetic fluxes are strengthened with each other, the leakage flux to the outside is small, and the swelling to peripheral devices can be reduced.

In such a configuration, when the flat comb type or the spiral print coil is arranged in close contact, the output side and the input side 1
In addition to the mutual inductance between the secondary and secondary, the mutual inductance between adjacent coils works effectively.
Conversion efficiency is significantly improved.

Incidentally, when a capacitor is inserted in the coil on the output side of the coil, the conversion efficiency is improved, but this is because the supply power consumed for excitation is reduced.

[0034]

As described above, according to the compact non-contact transmission device of the present invention, the electromagnetic induction effect between the coils facing each other through the air gap prevents the magnetic flux leakage due to the ferrite at least on the output side of the coil. Since transmission is prevented, the transmission efficiency is significantly improved. As a result, the thickness of the non-contact transmission unit and the compact non-contact transmission device in which the input side of the opposing coil is connected to the signal source are remarkably thinned, and effective applications in various fields are expected. .

Further, according to the present invention, since an electric circuit is laid on the ferrite core, it is possible to improve high-frequency characteristics and reduce parts such as a circuit board.

[Brief description of the drawings]

FIG. 1 is a side view of a small contactless transmission device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a receiving unit of the small contactless transmission device of FIG. 1;

FIG. 3 is a perspective view showing a transmission unit of the small contactless transmission device of FIG. 1;

FIG. 4 is a circuit diagram showing an equivalent circuit of the small contactless transmission device of FIG. 1;

[Explanation of symbols]

 2, 3 Coil 4, 5 Circuit conductor 6 Frequency conversion circuit 7 External signal power supply connection 10 Compact non-contact transmission device 11, 11 'Ferrite core 12 Rectifier / detector diode 13 Diode connection 14 Smoothing capacitor 15 Connection for smoothing capacitor Unit 16 resonance capacitor 17 connection unit for resonance capacitor 18, 19 external connection terminal unit 20 reception unit 21 resonance capacitor 22 connection unit for resonance capacitor 23, 24 external connection terminal unit 30 transmission unit

Claims (10)

[Claims] Claims 1. A coil opposing an air gap, one including an input side or a transmission side, and the other including an output side or a reception side,
In a non-contact transmission device for transmitting a signal or power or both simultaneously using an electromagnetic induction effect generated between the opposed coils, a substrate for providing the coil and an electric circuit including the coil is a ferrite powder molded body. A compact non-contact transmission device characterized by firing. 2. The compact non-contact transmission device according to claim 1, wherein said coil, a circuit wiring portion, and said substrate constituting said electric circuit are formed of NiO, CuO, ZnO, and F
The coil and the circuit wiring portion, which is a conductor of the electric circuit, are formed by a conductive paste containing Ag powder or Ag powder and Pd powder in a spinel ferrite green sheet containing e ₂ O ₃ as a main component. A compact non-contact transmission device characterized by being printed and integrally fired in air. 3. The compact non-contact transmission device according to claim 1, wherein each of the input side coil and the output side coil is at least one planar meander coil or planar spiral coil. A small contactless transmission device characterized by comprising: 4. The small non-contact transmission device according to claim 1, wherein the circuit wiring portion formed on the substrate has a connection portion for mounting a resonance capacitor on an output side. And a connection part for mounting a resonance capacitor, a detection and rectification diode, and a smoothing capacitor, and an external connection terminal on the input side. Transmission equipment. 5. The compact non-contact transmission device according to claim 1, wherein said coil, said circuit wiring portion, and said substrate are formed of an integrally fired ferrite core, and wherein a frequency used for transmission is used. Is a non-contact transmission device having a frequency of 100 kHz or more. 6. The compact non-contact transmission device according to claim 5, wherein the integrally fired ferrite core has a thickness of 0.1 to 5 mm.
A non-contact transmission device having a thickness in the range of: 7. The small contactless transmission device according to claim 1, wherein a contactless transmission system is used without a contact. 8. The compact non-contact transmission device according to claim 5, wherein the integrally fired ferrite core generates a leakage magnetic flux generated from an electric circuit on the input side and the output side.
A small-sized non-contact transmission device characterized by being made 0% or less. 9. The small contactless transmission device according to claim 1, wherein the coil of the substrate forms a component that forms the electric circuit or a component that is connected to the electric circuit. 0-2m on the other side opposite to the one side
m so that it can be arranged through a gap
Alternatively, a small-sized non-contact transmission device is configured so as to be arranged separately from the substrate. 10. The small non-contact transmission device according to claim 1, wherein the gap between the coils is 0 to 5 mm (not including 0). Contact transmission device.